From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 334FBC43381 for ; Fri, 22 Mar 2019 11:24:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 043FB218A2 for ; Fri, 22 Mar 2019 11:24:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553253854; bh=JJygba01lzbxCWm5WyrhVfdt+t9b0Fbx2M5OMDx4qC0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Xm6QPHLR8Eyw8g/DlfksmE5JEkRj7Cejlvu3I3MeIsNGT21LmMhD1wD8SlPKe/rGD Ogg6uzynISMGMs6/RDS9avJoUx/+3ngy3ZeAwl/ERj2xnFvdqi8yWz6LQy38jgPw0v 1Ea/gRaAF7iEWkyVdv/mTuGE5aztJBHviXUcFEso= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729072AbfCVLYM (ORCPT ); Fri, 22 Mar 2019 07:24:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:51180 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729051AbfCVLYJ (ORCPT ); Fri, 22 Mar 2019 07:24:09 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DFF222190A; Fri, 22 Mar 2019 11:24:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553253848; bh=JJygba01lzbxCWm5WyrhVfdt+t9b0Fbx2M5OMDx4qC0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=psPTXIzRtJ2L22Ao6LIExYELZ/jOpe/RsByvKrtEeOU8AcbM9hVRPcDsvTOVqBESW dmN9AqqF1J0Onyzozpp2WyoQRGlYFidKYOqpSoR5fIGckI4ZTGL0da/JcvEEfzl3VR NGED0rMULwvC0qbzOcwPm0ZoQz9BbbX1e8Dy1JAg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , "David S. Miller" Subject: [PATCH 3.18 090/134] vxlan: test dev->flags & IFF_UP before calling gro_cells_receive() Date: Fri, 22 Mar 2019 12:15:03 +0100 Message-Id: <20190322111216.646001507@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190322111210.465931067@linuxfoundation.org> References: <20190322111210.465931067@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 59cbf56fcd98ba2a715b6e97c4e43f773f956393 ] Same reasons than the ones explained in commit 4179cb5a4c92 ("vxlan: test dev->flags & IFF_UP before calling netif_rx()") netif_rx() or gro_cells_receive() must be called under a strict contract. At device dismantle phase, core networking clears IFF_UP and flush_all_backlogs() is called after rcu grace period to make sure no incoming packet might be in a cpu backlog and still referencing the device. A similar protocol is used for gro_cells infrastructure, as gro_cells_destroy() will be called only after a full rcu grace period is observed after IFF_UP has been cleared. Most drivers call netif_rx() from their interrupt handler, and since the interrupts are disabled at device dismantle, netif_rx() does not have to check dev->flags & IFF_UP Virtual drivers do not have this guarantee, and must therefore make the check themselves. Otherwise we risk use-after-free and/or crashes. Fixes: d342894c5d2f ("vxlan: virtual extensible lan") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/vxlan.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -1238,6 +1238,14 @@ static void vxlan_rcv(struct vxlan_sock } } + rcu_read_lock(); + + if (unlikely(!(vxlan->dev->flags & IFF_UP))) { + rcu_read_unlock(); + atomic_long_inc(&vxlan->dev->rx_dropped); + goto drop; + } + stats = this_cpu_ptr(vxlan->dev->tstats); u64_stats_update_begin(&stats->syncp); stats->rx_packets++; @@ -1246,6 +1254,8 @@ static void vxlan_rcv(struct vxlan_sock netif_rx(skb); + rcu_read_unlock(); + return; drop: /* Consume bad packet */